1. Field of the Invention
The present invention generally relates to a coin actuation mechanism for a coin-operated vending machine and, more particularly, is concerned with a dual coin actuation mechanism with angularly and axially offset coin slots and recesses.
2. Description of the Prior Art
U.S. Pat. Nos. 5,657,848 and 5,924,542 to Schwarzli and U.S. Pat. Appln. Pub. No. 2004/0206602 to Chang disclose prior art examples of dual-coin actuation mechanisms for a vending machine. Each of these prior art disclosures teaches a dual-coin actuation mechanism which has a front cover plate, a central shaft mounted through the cover plate for rotation about a central axis defined by the cover plate, a handle disposed adjacent to and exterior of the cover plate and rigidly connected to an outer end of the central shaft, and a coin carrier wheel mounted for rotation with the central shaft relative to the cover plate. The cover plate has first and second coin slots defined therethrough so as to be angularly displaced from, but axially aligned with, one another in a common plane disposed normal to the axis of rotation of the central shaft. The carrier wheel has first and second coin recesses angularly spaced apart from one another on a same one face of the carrier wheel but axially aligned with one another along the axis of rotation in the same common plane as the coin slots and also aligned with the corresponding coin slots when the carrier wheel is in a home position where the user can deposit a coin into each of the coin recesses. When first and second coins have been deposited into the first and second coin recesses on the carrier wheel, the handle can be turned by a user causing rotation of the central shaft and carrier wheel such that the deposited coins are carried by the carrier wheel about a common circular path, along the common plane of the coin slots and recesses, from which path the coins, in succession, can exit the carrier wheel at a discharge location and fall into a coin collection box. Such rotation of the central shaft also causes a gear mounted to an opposite end of the central shaft to simultaneously actuate a dispensing mechanism to cause an item to be dispensed from the vending machine to the user.
A problem exists, however, with the design of these prior art mechanisms. The first and second coin slots and recesses, by being axially aligned with one another in the common plane, means that necessarily the path of the trailing or second coin at some point during the turning of the handle and rotation of the central shaft and carrier wheel passes the first coin slot where the second coin is accessible to and can be removed by the user without jamming the mechanism, which results in loss of revenue to the owner of the vending machine.
To overcome this problem, the dual coin mechanism of the Schwarzli patents employs a movable rocker bar which extends across the path of the first coin, into and from its first coin slot, and thus blocks access to the first coin slot as the trailing or second coin passes it to thereby prevent removal of the trailing or second coin therefrom. Such extension of the rocker bar automatically occurs only when the trailing or second coin in the second coin recess is brought into alignment with the first coin slot. At all other times the rocker bar is retracted from the path of the first coin to and from the first coin slot. The dual coin mechanism of the Chang published patent application employs a pivotally-mounted blocking latch that pivotally yields from a normal blocking position across the path of the first coin into and from its first coin slot to a position offset from the path of the first coin in response to insertion of the first coin into the first coin slot but does not pivotally yield from the normal blocking position in response to an attempt to remove the second coin from the first coin slot when the carrier wheel has placed the second coin recess in alignment with the first coin slot.
While these prior art devices appear to be satisfactory in use for the specific purposes for which they were designed, none of them seem to provide the optimum solution for the problem at hand. Consequently, a need still exists for a device which provides an alternative solution to the aforementioned problem in the prior art without introducing any new problems in place thereof.